Well, I guess I may as well throw in my 2 cents since i have a little experience on the subject.
As far as danger goes, the only danger I can see is lack of blood circulation and vein damage due to extended periods of pressure on a single spot.
If your penis is cold to the touch after you have been in your ADC for a while, or if there is fluid buildup, or if you start getting negative PI’s, I would say that you should tone down on the all day thing. Maybe do it in sets of an hour on, hour off or something.
If this is not the case, I would say judge by how your body reacts. If the pressure of the ADC is light enough and you keggel regularly to get the blood flowing through the penis i don’t see why this should cause too much of a problem.
I do something similar, except i substitute ADC for 4 or so very light 5 minute workouts through the day, mostly just stretching and dry jelq.
Good luck and let us know how it goes!